WASHINGTON -- Oklahoma Republican Sen. Tom Coburn has effectively blocked a resolution to honor environmental author Rachel Carson on the 100th anniversary of her birth, saying that her warnings about environmental damage have put a stigma on potentially lifesaving pesticides, congressional staffers say.

Sen. Benjamin Cardin, D-Md., had intended to submit a resolution celebrating Ms. Carson, author of the 1962 book "Silent Spring," for her "legacy of scientific rigor coupled with poetic sensibility." Ms. Carson, a native of Springdale, Pa., near Pittsburgh, and a longtime resident of Silver Spring, Md., who died in 1964, would have turned 100 this Sunday.

But Mr. Cardin has delayed the legislation, a spokeswoman said, because Mr. Coburn has signaled that he will use Senate rules to halt it.

"We have not submitted the resolution yet because we understand that Senator Coburn has said he will block it," Cardin spokeswoman Susan Sullam said. She said Mr. Cardin is considering whether to submit the bill later this week.

In a statement on his Web site Tuesday, Mr. Coburn confirmed that he is holding up the bill. In the statement, he blames Ms. Carson for using "junk science" to turn public opinion against chemicals, including DDT, that could prevent the spread of insect-borne diseases such as malaria, which is spread by mosquitoes.

Mr. Coburn, whose Web site says he is a physician specializing in family medicine, obstetrics and allergies, said in the statement that 1 million to 2 million people die of malaria every year. "Carson was the author of the now-debunked 'The Silent Spring,' " Mr. Coburn's statement reads. "This book was the catalyst in the deadly worldwide stigmatization against insecticides, especially DDT."

The controversy over Mr. Cardin's resolution is the second spat on Capitol Hill this year over Ms. Carson's legacy. In late April, a House bill that would name a post office after Ms. Carson in her hometown of Springdale received 53 "nay" votes. In news reports, some of those voting against the measure cited similar concerns about Ms. Carson's impact on the decline of DDT use.

Mr. Coburn said on his Web site Tuesday that he is also blocking that bill, which was referred to the Senate after the House passed it. He did not give details. Under Senate rules, any senator may hold up legislation scheduled as a "unanimous consent" measure for quicker-than-usual passage.

Ms. Carson's book, which begins with a scene of a town in which all of nature is silenced by pollution, examines the effects that industrial-age chemicals were having on human and animal health. She focuses particularly on the effects that DDT, a pesticide used to kill mosquitoes and other insects, appeared to be having on the reproduction of birds.

Her book is credited with inspiring the formation of the Environmental Protection Agency in 1970 and the banning of most uses of DDT in the United States in 1972. Since her death from cancer, she has come to be celebrated as a hero by the environmental movement and as the inspiration for the modern, aggressive strain of advocacy for nature.

At the same time, however, some experts have criticized her for being too alarmist about DDT and inspiring officials to ban a chemical that could save numerous lives.

George Washington University research professor Linda Lear, who wrote a biography of Ms. Carson, said Ms. Carson did not call for a total halt to the use of DDT, but did urge that it not be widely sprayed in places where the damage could outweigh the benefits.